Metilprednizolon ve Sürfaktanın Akut Solunum Sıkıntısı Sendromunda Terapötik Etkileri

Abstract

Objective: To compare the efficacy of methylprednisolone and surfactant in early stages of acute lung injury in rats and to determine whether acute respiratory distress syndrome (ARDS) development and its responsiveness to medical treatment could be assessed by brain natriuretic peptide (BNP) and pro-N type BNP. Material and Methods: Fourty rats were randomly allocated into one of five groups, with 8 replicates. Rats in the baseline group (group B) were not subjected to either tracheotomy or ARDS induction, whereas rats in sham group (group N) were subjected only to tracheotomy. After tracheotomy and induction of ARDS by acid aspiration, remaining rats (n= 24) were treated with either a single dose of methylprednisolone (20 mg/kg, group M) or surfactant (100 mg/kg, group S) or left untreated (group A). Six hours later, arterial blood samples were collected for blood gases, BNP, and Pro N-Type BNP measurements. Results: Sham tracheotomy did not affect PaO2/FiO2 ratio, BNP and pro-N type BNP levels, or the acute lung injury (ALI) score. ARDS induction decreased PaO2/FiO2 ratio by 62% and increased BNP and pro-N type BNP levels, as well as ALI score by 3.5, 2.3, and 2.4-folds, respectively. PaO2/FiO2 in group A was significantly lower than the controls (p< 0.001). We noted an increase in PaO2/FiO2 with methylprednisolone and surfactant treatment (p< 0.001). Both methylprednisolone and surfactant treatments increased PaO2/FiO2 ratio and decreased BNP and pro-N type BNP levels. There was an increase in BNP in the ARDS group (p< 0.001). Compared to the ARDS group, significant reductions were observed in the methylprednisolone and surfactant groups (p< 0.001, p< 0.05). BNP value in group M was lower than the group S (p< 0.05). Pro N-Type BNP increased in rats of the ARDS group (p< 0.001). ALI score of the ARDS group increased significantly in comparison to the normal group (p< 0.001). However, both treatment modalities failed to reduce Pro N-Type BNP and ALI score. Blood PaO2/FiO2 ratio showed negative correlations with BNP (r= -0.78, p< 0.001) and pro-N type BNP (r= -0.81, p< 0.001) levels. Conclusion: PaO2/FiO2 ratio increased whereas BNP level decreased following intraperitoneal methylprednisolone and intratracheal surfactant administration in ARDS-induced rats. PaO2/FiO2 ratio and BNP may be considered as markers during treatment and follow-up of patients with ARDS.